http://www.digitaljournal.com/life/health/strange-slimming-effect-of-sweet-potato-waste/article/481405

Strange slimming effect of sweet potato waste

Posted Dec 10, 2016 by Tim Sandle
Obviously eating sweet potatoes is not going to make you slim, especially when accompanied by other starchy food. However, a study on mice suggests the water left over from cooking sweet potatoes may have slimming effects.
Sweet potato hashbrowns.
Sweet potato hashbrowns.
The study has used mice fed a high fat diet (to simulate the effects of obesity in a person.) One group of mice were fed sweet potato peptide. This peptide is produce following the enzymatic digestion of the potato proteins in the water, released during the cooking (by boiling) process.
Sweet potatoes are one of the world’s most popular crops and 15 percent of the global supply is used in the manufacture of processed foods and alcoholic beverages in Japan. The wastewater from the cooking process tends to be discarded and adds to the environmental burden of the disposal of waste.
The study into the potato waste was conducted by Dr. Koji Ishiguro (National Agriculture and Food Research Organization in Japan.) Here the scientist explains: "We hypothesized that these [potato waters] could affect body weight, fat tissue and other factors." explained Dr. Ishiguro. "Finding alternative uses for the sweet potato proteins in wastewater could be good for the environment and industry, and also potentially for health."
With the study, the scientists fed three sets of mice high fat diets. One group was given sweet potato peptide at a high concentration; one was given the same protein digest at a lower concentration; and a final group was not given any additional substance. This ran for 28 days, after which time the mice were assessed for liver mass and fatty tissue deposits, as well as for cholesterol and triglyceride levels. Further analysis was made of the hormones leptin (which controls hunger) and adiponectin (which regulates metabolic syndrome.)
All mice given the sweet potato peptide had lower body weight and liver mass compared with the control group, leading to the finding that sweet potato peptide helps to suppress appetite and control the metabolism of fats.
While the effect has been observed in mice, reared under laboratory conditions, it is not known whether the same weight loss would occur with people. This is likely to form part of a future research project. Moreover, finding a use for potato water could help to lessen the environmental impact.
The research has been published in the journal Heliyon, and the research paper is titled “Effects of a sweetpotato protein digest on lipid metabolism in mice administered a high-fat diet.”